Considerable interest, as a potential tool material, has been aroused in the use of abrasion resistant materials which consist of or contain boron, usually in the form of a boride of titanium. The material is usually fabricated by cementing together the titanium boride material with a metallic binder which may include iron, nickel, or cobalt. However, utilizing such metal binders has not met with success because of (a) unsatisfactory strength and hardness at high temperatures, and (b) the processing temperature required for formation of the bond between the particles is too high (see U.S. Pat. No. 3,256,072).
To create a higher density sintered body with higher mechanical strength, the art has attempted to replace such metal binders with a combination of two separate components, the first of which includes a nickel phosphide or nickel phosphorus alloy, and the second consists of a metal selected from the group comprising chromium, molybdenum, rhenium, and the like, or a metal diboride, chromium diboride, or zirconium diboride (see U.S. Pat. No. 4,246,027). However, this particular replacement and chemistry has not proved entirely successful because the resulting combination of hardness and strength still remains below desired levels and still requires expensive hot pressing to achieve densification.
But, more importantly, the presence of phosphorus in this prior art material can make the material unsuitable for machining aluminum based materials due to embrittlement.